/* Copyright (c) 2015, bugyo
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright notice,
*    this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
*    this list of conditions and the following disclaimer in the documentation
*    and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: print-vxlan-gpe.c,v 1.5 2024/09/02 16:15:33 christos Exp $");
#endif

/* \summary: Generic Protocol Extension for VXLAN (VXLAN GPE) printer */

/* specification: draft-ietf-nvo3-vxlan-gpe-10 */

#include <config.h>

#include "netdissect-stdinc.h"

#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "extract.h"

static const struct tok vxlan_gpe_flags [] = {
   { 0x08, "I" },
   { 0x04, "P" },
   { 0x02, "B" },
   { 0x01, "O" },
   { 0, NULL }
};

#define VXLAN_GPE_HDR_LEN 8

/*
* VXLAN GPE header, draft-ietf-nvo3-vxlan-gpe-01
*                   Generic Protocol Extension for VXLAN
*
*     0                   1                   2                   3
*     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
*    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*    |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
*    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*    |                VXLAN Network Identifier (VNI) |   Reserved    |
*    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/

void
vxlan_gpe_print(netdissect_options *ndo, const u_char *bp, u_int len)
{
   uint8_t flags;
   uint8_t next_protocol;
   uint32_t vni;

   ndo->ndo_protocol = "vxlan_gpe";
   ND_PRINT("VXLAN-GPE, ");
   if (len < VXLAN_GPE_HDR_LEN) {
       ND_PRINT(" (len %u < %u)", len, VXLAN_GPE_HDR_LEN);
       goto invalid;
   }

   flags = GET_U_1(bp);
   bp += 1;
   len -= 1;
   ND_PRINT("flags [%s], ",
             bittok2str_nosep(vxlan_gpe_flags, "none", flags));

   /* Reserved */
   bp += 2;
   len -= 2;

   next_protocol = GET_U_1(bp);
   bp += 1;
   len -= 1;

   vni = GET_BE_U_3(bp);
   bp += 3;
   len -= 3;

   /* Reserved */
   ND_TCHECK_1(bp);
   bp += 1;
   len -= 1;

   ND_PRINT("vni %u", vni);
   ND_PRINT(ndo->ndo_vflag ? "\n    " : ": ");

   switch (next_protocol) {
   case 0x1:
       ip_print(ndo, bp, len);
       break;
   case 0x2:
       ip6_print(ndo, bp, len);
       break;
   case 0x3:
       ether_print(ndo, bp, len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL);
       break;
   case 0x4:
       nsh_print(ndo, bp, len);
       break;
   default:
       ND_PRINT("ERROR: unknown-next-protocol");
       goto invalid;
   }

       return;

invalid:
   nd_print_invalid(ndo);
}